What are gullies, and do you need a gully trap?

What are gullies, and do you need a gully trap?

A gully is a drainage fitting with an open top, a definite base and an outlet to one or more sides. Depending on the type of gully, they can be used to connect wastewater outlets or stormwater/rainwater outlets to suitable drains. They can also be used to drain surface water from areas susceptible to flooding.

There are two main types of gullies which include:

  • Road Drainage Gullies
    These are designed to discharge surface water from roads and highways, where large volumes of surface water can build up. Road gullies are designed to be much more robust than domestic gullies in order to withstand the heavier trafficked environments in which they are installed. They are usually made from concrete or HDPE.

  • Domestic Gullies
  • Domestic gullies are designed to discharge surface water from your garden, rainwater from your guttering, and grey wastewater from your washing machine, dishwasher, bath, shower and sink into the appropriate drains. They are usually found under a downspout or external grey wastewater discharge point.

    What are gully traps?

    A gully trap refers to an aspect of the internal design. It is a basin in the ground which receives piped wastewater from inside your home before it is emptied into the wastewater network. The basin has a seal which traps the water in order to prevent foul odours from escaping back out of the drain and into the air.

    The most common types of gully traps are the P Trap Gully and the Bottle Gully. In general, they both do the same job but there are some important differences.

  • P Trap Gully
    The P Trap Gully is the length of the pipe that has been moulded into a shape that resembles the letter “P”. This acts in a similar way to the U-bend beneath your kitchen sink, in that it forms a seal between the opening of the drain and the wastewater further down the pipe, which again prevents unpleasant gases.

    Available in 45-degree bend or 90-degree bend to the outlet, the P trap gully is most commonly used to collect rainwater from a downspout when connected to grated drainage fitting called a hopper.

    The main downside to this is that if the P trap gully or drain connected to it gets blocked it can’t be cleared with a drain rod, therefore overtime debris can build up and cause blockages. If this happens you will need to call a drainage specialist.

  • Bottle Trap Gully
  • The bottle trap gully works in a similar way to the P trap but doesn’t require the tight bend in the pipe to trap the water, therefore solves the rodding issue. The design still traps the water to prevent smells, but it does so with a removable sleeve that makes it easier to clean out silt or debris. Bottle gullies are ideal for rainwater and wastewater use and most commonly found around newer properties or where old gullies have had to be replaced. 

    How can we help?

    We offer a range of Gullies including Bottle Gullies, Road Gullies, Yard Gullies, Concrete Gullies, HDPE Gullies. For more information please call us on 0121 351 3230  and one of our experts will be happy to help you pick the right products for your project specification. 

    Alternatively, fill out our enquiry form: